Rotary drum granualtors improve pelletization rates through structural innovation as follows:

1. Internal structure optimization: An annular intermediate retaining ring and a discharge retaining ring are installed on the inner wall of the drum, dividing the drum interior into a heating and humidification zone and a tumbling and balling zone. The intermediate retaining ring ensures full contact between the material and the steam, achieving uniform heating and humidification; the discharge retaining ring prolongs the tumbling time and amplitude of the material, increasing the pelletization rate.

2. Increasing material residence time: Appropriately reducing the drum speed prolongs the material's residence time within the drum, giving it more opportunities to form pellets.

3. Controlling material moisture content: Based on the initial moisture content of the material, spraying bacterial solution, molasses, or incorporating rice husk powder or composted straw can be used to maintain the material moisture content within an appropriate range.

4. Adjusting the drum inclination: Adjusting the drum inclination angle based on the drum diameter and the production requirements of the organic fertilizer production line ensures more complete material tumbling within the drum, thereby improving the pelletization rate. 5. Binder Addition: Depending on the type of raw material, an appropriate amount of binder, such as humic acid, starch ether, bentonite, or CMC, is added to enhance material adhesion and pelletization efficiency.

6. Acid Addition System: An acid addition pipe is installed within the granulation chamber. High-pressure air is introduced into the acid storage tank via an air compressor, spraying the acid onto the material to improve pelletization.

7. Movable Weight Design: A movable weight is installed within the drum. As the drum rotates, the movable weight moves up and down, causing the inner liner to rise and fall, shaking off the material and preventing it from adhering to the inner liner.

Through these structural innovations, the rotary drum granulator can effectively improve pelletization efficiency, enhance production efficiency, and improve product quality.